"When I saw him I spoke and he handed me a cap, a jumper and overalls, which I put on within ten feet of you, Mr. Warden, while you were in the yard. Later Mr. Hatch called me, presumably as a workman, and together we went out the gate to get something out of the wagon. The gate guard let us pass out readily as two workmen who had just passed in. We changed our clothing and reappeared, asking to see you. We saw you. That's all."
There was silence for several minutes. Dr. Ransome was first to speak.
"Wonderful!" he exclaimed. "Perfectly amazing."
"How did Mr. Hatch happen to come with the electricians?" asked Mr. Fielding.
"His father is manager of the company," replied The Thinking Machine.
"But what if there had been no Mr. Hatch outside to help?"
"Every prisoner has one friend outside who would help him escape if he could."
"Suppose — just suppose — there had been no old plumbing system there?" asked the warden, curiously.
"There were two other ways out," said The Thinking Machine, enigmatically.
Ten minutes later the telephone bell rang. It was a request for the warden.
"Light all right, eh?" the warden asked, through the 'phone. "Good. Wire cut beside Cell 13? Yes, I know. One electrician too many? What's that? Two came out?"
The warden turned to the others with a puzzled expression.
"He only let in four electricians, he has let out two and says there are three left."
"I was the odd one," said The Thinking Machine.
"Oh," said the warden. "I see." Then through the 'phone: "Let the fifth man go. He's all right."